US Patent 7521858 Organic EL display and method of manufacturing the same

An organic EL display includes a substrate, and organic EL elements arranged on the substrate. Each organic EL element includes an anode, a cathode, an emitting layer made of an organic material and interposed therebetween, and a hole transporting layer made of an organic material and interposed between the emitting layer and the anode. The hole transporting layer includes a first layer and a second layer facing the substrate with the first layer interposed therebetween. The second layer is equal in compositions with the first layer and different in degrees of crystallinity from the first layer.